Aircraft engines used to propel aircraft through certain routes often experience significant fouling due to heavy environmental particulate matter intake during flight, idling, taxiing, take-off, and landing. Environmental fouling degrades performance in turbine components of such aircraft engines. For example, one known mechanism for fouling is the increased roughness of turbine components caused by mineral dust ingestion. Specifically, this increased roughness can result from the formation of micropits caused by particle impact. Subsequently, mineral dust particles accumulate in these pits and block cooling passages by forming layers of fouling material therein. High temperatures on surfaces in downstream stages of the turbine result in thermal alteration and solid-state mineral reactions of the accumulated mineral dust particles, which forms a calcia, magnesia, alumina, silica (CMAS) based reaction product. Once reaction products have formed and cooled, they may become very difficult to remove. Even mineral dust particles or CMAS precursors that do not form a CMAS reaction product may still travel through relatively low-temperature portions of the engine. These dust particles may subsequently cause substantial damage through abrasion or oxidation.
Typical methods for cleaning an engine require attaching existing systems to the engine only after a flight has concluded. Such systems may require complete or partial disassembly of the engine. Often, all or some of the engine must be removed from the wing or aircraft structure to which it is mounted. Significant time and energy may be required to adequately clean internal portions of the engine, especially if CMAS accumulation or buildup has occurred. Also, although CMAS buildup becomes harder to remove once it has cooled, the engine may not be disassembled until significant cooling has occurred. The cumbersome and time-consuming nature of these methods may cause cleaning to take place only intermittently. Even when they do occur, the cumbersome and time-consuming nature of typical methods may reduce the time available to perform other post-flight maintenance operations. Moreover, they may be completely unable to address mineral dust that accumulates outside of a combustible gas flow path of the engine.
Accordingly, further improvements to cleaning methods and systems are desired. Methods and systems that provide cleaning to an engine while mounted to an aircraft structure such as a wing would be useful. Methods and systems that provide cleaning to an engine during flight or immediately thereafter would also be useful.